Marine propulsion

ABSTRACT

A marine propulsion unit, including a duct and a center body which is located within the duct. A combustion chamber is positioned in the center body and receives fuel and compressed air from a source located in the hull of the ship. A turbine also positioned in the center body drives an impeller at the inlet of the duct. Wing shaped arms extend laterally of the duct with each arm having a span-wise nozzle so that water can flow through the lateral arms. The exhaust of the turbine flows through the arms and is mixed with the water flowing through the nozzle. The direction of the efflux from the nozzle can be varied to provide thrust vectoring.

0 United States Patent 11 1 1111 3,889,622 Scott-Scott June 17, 1975 1 MARINE PROPULSION 3.171.379 3/1965 SChfill. Jr. et al. 114/665 H A 3.365 89l l/l968 Williams [IS/l3 [75] Inventor John Lanfear Scott-Scott, 3504'649 W970 Scherer H 4/665 H Bulkmgmm England 3,590,762 7 1971 Yuan 114/665 H [73] Assignee: Rolls-Royce (1971) Limited,

London SWIY 4JR E l d Primary Examiner-Trygve M, Blix Assistant ExaminerJesus D. Sotelo [22] Flled' Sept 1974 Attorney, Agent, or FirmCushman, Darby & [Zl] Appl. No.: 507,193 Cushman Related US. Application Data 57 STRA [63] Continuation-impart of Ser. No. 329342, Feb. 5, 1 AB CT 1973, abandoned A marine propulsion unit, including a duct and a center body which is located within the duct A combus- {301 Foreign Application Priority Data tion chamber is positioned in the center body and re- Fcb I l 1972 United Kingdom n 6474/72 ceives fuel and compressed air from a source located in the hull of the ship. A turbine also positioned in the [52] Cl V 15/1 1; [14/665 H center body drives an impeller at the inlet of the duct 151 Int. Cl t. B63h 5/00 Wing Shaped arms extend laterally of the duct with [58) Field of searchuwmm [14/665 H 67 A 150 each arm having a span-wise nozzle so that water can 114/15 115/11 12 R 12 A 1,134 i flow through the lateral arms. The exhaust of the tur- 60/221422 330 334; 244/42 CC 42 CA bine flows through the arms and is mixed with the water flowing through the nozzle. The direction of the [56] References Cited efflux from the nozzle can be varied to provide thrust UNITED STATES PATENTS veconng' 3,055,331 9/1962 Singelmann ll4/66.5 H 5 Claims, 12 Drawing Figures PATENTEDJUN 1 7 ms SHEET F/GJ a ""'//IIA MARINE PROPULSION This is a continuation-in-part of copending US. patent application, Ser. No. 329,342, filed Feb. 5, 1973, now abandoned, and assigned to the common assignee herewith.

BACKGROUND OF THE INVENTION This invention relates to marine propulsion units for vessels such as hovercraft and hydrofoils and is particularly but not exclusively concerned with propulsion units of large horsepower of the order of 100,000 HP.

The present invention provides a propulsion unit for a marine vessel. The propulsion unit comprises a duct and a centerbody located within the duct, the centerbody having located within it combustion means arranged to receive fuel and compressed air from sources located remotely of the centerbody. Turbine means are arranged to drive an impeller located in the inlet of the duct, and at least one wing-like arm extends laterally of the duct, the arm having a span-wise extending nozzle through which water is capable of flowing. The exhaust from the turbine means is arranged to flow through the arm and to be mixed with the water flowing through the nozzle over substantially the whole of the span-wise width of the nozzle.

Preferably, the propulsion unit (or units where a number of units are required to provide adequate power) is attached to the marine vessel by a hollow streamlined strut through which the supplies of fuel and compressed air can pass in suitable conduits.

The source of compressed air is preferably located in the hull of the vessel and may take the form of any one of a number of suitable sources, for example, a single or twin spool gas generator powered power turbine driving a compressor, the output from which is supplied to the combustion means or a gas turbine engine having a suitably sized compressor so that a large proportion of the compressor output can be supplied to the combustion means, or a gas turbine engine in which the hot exhaust gases are fed direct to the combustion means. In the latter case, the compressor will require one or more extra stages and the turbine will need to have a relatively low pressure drop so that the final pressure of the exhaust gases is similar to that of the first described source of compressed air.

The output from the nozzle or nozzles in the arm may be varied in direction to control lift or to act as thrust vectoring by having a row of control nozzles in the divergent part of the nozzle. Compressed air tapped from the combustion means air supply can be blown through the nozzles and thus cause the flow to separate from one of the nozzle walls.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be more particularly described with reference to the accompanying drawings in which FIG. 1 shows a diagrammatic perspective view of one form of propulsion unit according to the present invention;

FIG. 2 is a section on line 22 of FIG. 1;

FIG. 3 is a section on line 33 of FIG. 1;

FIG. 4 is a modified form of the section shown in FIG. 3;

FIG. 5 is a side elevation in greater detail of the proplsion unit centerbody;

FIG. 6 is a section on line 66 in FIG. 5;

FIG. 7 is a plan view of FIG. 5;

FIG. 8 is a section through the wing-like arm of the propulsion unit;

FIG. 9 is a section on line 9-9 of FIG. 8;

FIG. I0 is a section on line l0-l0 of FIG. 8;

FIG. I] is a section through a modified form of the wing-like arm; and

FIG. 12 is a section on line l2l2 of FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 to 3, a propulsion unit 10 is attached to a streamlined hollow strut 12 which is secured to a vessel generally designated by the numeral 13. The propulsion unit 10 comprises a duct 14 in which a center body 16 is located, the center body 16 containing combustion means 18 and turbine means 20 arranged to drive an impeller 22 by means of a shaft 24. The combustion means 18 is arranged to receive supplies of fuel and compressed air through respective conduits 26, 28 located in the strut 12.

The impeller 22 is a conventional or fully-cavitating impeller with two or more rows of conventional noncavitating stator blades and the downstream end of the duct is shaped as a nozzle, so that the combination of the impeller, duct and nozzle acts as a conventional water jet.

Two wing-like arms 30 extend laterally from each side of the duct I4. Each arm is hollow and the exhaust from the turbine means is arranged to flow into each arm. Each arm has a span-wise extending nozzle 32, as shown more clearly in FIG. 3, through which water is capable of flowing. Means are provided to ensure that the exhaust gases are passed into substantially the whole of the span-wise length of the nozzle, for example the walls of the nozzle may be porous.

Referring to FIGS. 5, 6 and 7, a plenum chamber 50 is provided within the centerbody I6 and is formed by two cone-like structures 52 and 54, the upstream diameters of which correspond respectively to the blade root and blade tip diameters of the turbine means 20.

Two aerofoil section shaped ducts 56 are flared into and connected with the outer cone structure 54 on opposed sides of the cone structure and extend through the wall of the duct 14 into each arm 30. Three flow diverters 58 are fixed inside each duct 56 and extend slightly into the plenum chamber 50. The inboard ends of the flow diverters are curved in the upstream direction as seen in plan view in FIG. 7 and the ends are also curved in elevation as seen in FIG. 6 to provide stiffness.

Referring to FIGS. 8, 9 and 10, each duct 56 goes into the respective arm 30 and the duct is then split where the nozzle 32 extends through the arm into upper and lower portions 56a, 56b, respectively. The interior walls of the ducts 56a, 56b are porous or may be apertured so that gas can flow into the nozzle 32.

FIG. 11 and FIG. 12 show a modified form of the arrangement shown in FIGS. 8 to 10 in which the duct 56 is split into three ducts, an upper and lower duct 56a, 5617, respectively, as in FIG. 8 and a central duct 56c which forms a centerbody in the nozzle 32, both walls of the central duct 560 are louvered and the interior walls of the ducts 56a, 56b are also louvered so as to assist in the diffusion of air into the water across the nozzle 32.

In operation hot exhaust gas from the turbine means flows into the plenum chamber 50 and is directed into the ducts 56 by the flow diverters 58. The hot gas then flows along the ducts 56 and is split into two portions and passes into the ducts 56a, 56b and thence through the inner wall of these latter ducts into the water flowing through the nozzle 32.

The direction of the efflux from the nozzles can be varied for lift control or thrust vectoring by means of two rows of apertures 34, 36 at the top and bottom. respectively. of each nozzle at the divergent portion of each nozzle through which compressed air can he blown. This is achieved by connecting the apertures to the Conduit 28 and having valves 38, 40 which are independently operable so that compressed air can be blown through one or another of the rows of apertures. the result being that the flow becomes attached to the opposite wall of the divergent portion of the nozzle to that from which the compressed air is issuring.

While the present invention has been disclosed in connection with the preferred embodiments thereof, it should be understood that there are other obvious variances of the invention which fall within the spirit and scope thereof as defined by the appended claims.

What is claimed is:

l. A marine propulsion unit comprising a duct and a centerbody located within the duct. the centerbody having located within it combustion means arranged to receive fuel and compressed air from a source located remotely of the centerbody and turbine means arranged to drive an impeller located in the inlet of the duct, at least one wing-like arm extending laterally of the duct being provided, the said arm having a spanwise nozzle which extends over the whole chord of said arms. water being capable of flowing through said nozzle, the exhaust from the turbine means being arranged to flow through said arm to be mixed with water flowing through said nozzle over substantially the whole of the span-wise width of the said nozzle.

2. A propulsion unit as claimed in claim 1 in which the outlet flow from said nozzle is variable in direction.

3. A propulsion unit as claimed in claim 2 in which said nozzle has a convergent-divergent outlet portion of the nozzle. a supply of compressed air being selectively directed to one of the rows of apertures to control the direction of flow of the nozzle efflux.

4. A marine vessel including a propulsion unit as claimed in claim I, the propulsion unit being attached to the vessel by a streamlined hollow strut.

5. A marine vessel as claimed in claim 4 in which the vessel is an hydrofoil. 

1. A marine propulsion unit comprising a duct and a centerbody located within the duct, the centerbody having located within it combustion means arranged to receive fuel and compressed air from a source located remotely of the centerbody and turbine means arranged to drive an impeller located in the inlet of the duct, at least one wing-like arm extending laterally of the duct being provided, the said arm having a span-wise nozzle which extends over the whole chord of said arms, water being capable of flowing through said nozzle, the exhaust from the turbine means being arranged to flow through said arm to be mixed with water flowing through said nozzle over substantially the whole of the span-wise width of the said nozzle.
 2. A propulsion unit as claimed in claim 1 in which the outlet flow from said nozzle is variable in direction.
 3. A propulsion unit as claimed in claim 2 in which said nozzle has a convergent-divergent outlet portion of the nozzle, a supply of compressed air being selectively directed to one of the rows of apertures to control the direction of flow of the nozzle efflux.
 4. A marine vessel including a propulsion unit as claimed in claim 1, the propulsion unit being attached to the vessel by a streamlined hollow strut.
 5. A marine vessel as claimed in claim 4 in which the vessel is an hydrofoil. 